Windows installed on aircraft are subject to repeated temperature and pressure cycling as the aircraft climbs to cruising altitude and is pressurized and then descends for landing and is depressurized. A window may have one or more anomalies, such as inclusions present from manufacturing and/or nicks or scratches incurred during operation. Such anomalies can impact appearance or performance of aircraft window. Early detection of anomalies may ensure that their impact is minimized. One example of inclusions are zirconium crystals, which are typically tiny (e.g., about 0.005 inches in length) and clear, so they are difficult to detect with traditional optical methods. An anomaly may grow larger over time and operational cycles, and detecting and dealing with small anomalies is the preferable approach.